Tail-plane and the like for aircraft



- H. SCOTT-PAINEr TAIL PLANE AND THE LIKE FOBAIRCRAFT. APPLICATION FILED MAR. 11, 1920.

Patented Apr. 19, 1921.

' STA TAIL-PLANE AND THE LIKE FORQAIRCRAFT.

Specification of Letters Patent.

Application filed March 17, 1920. Serial No. 366,459.

To all whom it may concern:

Be it known that I, Hunnnr Soorr- PAINE, a subject of the King of England, residing at Southampton, in the county of Hants, England, have invented certain new and useful Improvements in Tail-Planes and the like for Aircraft, of which the following is a specification.

The present invention relates to tailplanes and the like for aircraft, its object being to provide an improved construction of tail-plane and the like, that is to say any plane which is situated to the rear of the main planes and may therefore be designated a trailing-plane.

Heretofore it has been customary to construct a trailing plane-structure with planes of neutral section and to obtain any lifting or depressing effect therefrom by to the plane an appropriate tilt.

The, present invention provides a multiplane tail or other trailing plane-structure for aircraft having one or more of the planes formed with a lifting camber.

The present invention further provides a tail unit or other trailing plane-structure for aircraft having one or more of the planes formed with a'lifting camber and one or more with areversed lifting camher, or in the case of a monoplane tail unit, the single plane may have a reversed lifting camber.

A further feature of this invention is the arrangement, in an aeroplane or other aircraft, of a multiplane tail or other multiplane trailing plane-structure provided with one or more planes formed with a reversed lifting camber and so situated with giving relation to the propeller or airscrew that the said plane or planes of reversed lifting camber are more strongly exposed to the slip-stream than the remaining plane or planes of the said structure.

This invention is of particular use in the case of a tail-plane for craft of the flying boat type when leaving the water because the center of resistance is then at its low est point (due to the hull resistance in the water) and the correction for the enginethrust requires to be greatest. The invention is of special value in craft having pusher engines but can also be used in those having tractor engines.

The accompanying drawing is a diagrammatic llustration of the application of this lnve-ntlon to a flying-boat.

The hull of the boat is indicated at 10 with any usual or desired type of mamplane-structure at 11 and 12; the engine 13 w th theairscrew 14 is mounted, as is usual wlth flying boats, above the hull and between the main planes, the air-screw'being either a tractor as shown in full lines or a pusher as shown in brokenlin'es.

In this construction the tail unit is. of blplane formation, whereof the lower plane 20 has a lifting camber and the upper plane 21 has a reversed lifting camber, that is to say a lifting camber employed upside down so as normally to give a depression effect at the after end of the vessel. The tail unit 1s situated at the rear of the propeller 14: and at such a level that the lower plane 20 is either partially screened by one of the main planes, or is otherwise so positioned that 1t is less exposed to the slip-stream from the airscrew than the upper plane 21: The elevator control of the machine may be effected by the usual elevator planes 22 hinged to the rear edge of the tail planes 20, 21 and controlled in the ordinary manner by the pilot.

I The employment of a bi-plane tail unit naturally tends to greater fore-and-aft stability of the machine but it will be seen that since the plane 21 is more exposed to the slip stream from the airscrew than the lower plane 20, it will tend automatically to correct the balance of the machine when the latter is disturbed by varying engine thrust; an increase of the engine thrust tends to cause the machine to dive, but the effect of the increased slipstream on the upper plane 21 of the tail unit produces an increased downward thrust on the tail unit thereby correcting or tending to correct the tendency of the machine to dive.

Various modifications may be made in the exact arrangement and disposition of the tailplane or planes, and the invention is not restricted to the application of the hereinbefore described features to a tail unit, but includes their application to any trailing plane-structure, that is to say a trailing structure having one or two or more operative planes.

Patented Apr. 19, 1921.

to secure by Letters atent is planes, one of which is formed with a re- 1. In an aircraft, a trailing plane-strucversed lifting camber and so situated with ture provided with a plane formed with a relation to the airscrew that the said plane 5 reversed lifting camber and sosituated with With reversed lifting camber is more relation to the air-screw that the said plane strongly exposed to the slip-stream than the 15 of reversed lifting camber is fully exposed? remaining plane area of said structure;

to the slip-stream. Intestimony whereofI affix my signature. 2; In an aircraft, a multiplane trailing a HUBERT SCOTT-PAINE.

What I claim as m invention and desire structure provided with a plurality of 10 

